1. Field of the Invention
The invention herein pertains to window frame extrusions which are used with window installations, wall systems, and doors and particularly pertains to window frame extrusions having a thermal insulation component.
1. Description Of The Prior Art And Objectives of the Invention
Metal window frames are increasingly used in replacing wooden window frames due to their greater strength, durability and ease of assembly. Such metal window frames are commonly formed from aluminum extrusions, which are manufactured by forcing molten aluminum through a die. By using differently shaped dies, nearly any shape of extrusion imaginable can be created. Due to the limitless shape possibilities, extruded aluminum window frames are much more versatile than wooden window frames. However, wooden window frames do have one distinct advantage over aluminum extrusions in that wooden window frames are much better insulators. To help alleviate the problems associated with heat loss, aluminum window frame extrusions commonly include an insulation component to prevent heat from being conducted to the outdoors from a heated building or from the outdoors into an air conditioned building.
Many conventional insulated aluminum extrusions are created by first manufacturing an extrusion having a bridge connecting two halves of the extrusion together. Adjacent to the bridge is a longitudinal channel for holding insulation. Insulation such as a suitable polyurethane is poured into the channel above the bridge and then is allowed to harden or cure. The bridge is then removed, so as to prevent heat loss, by milling or sawing leaving the two halves of the aluminum extrusion separated by a hardened polyurethane thermal barrier. Sometimes the bridge is removed in part leaving small segments connecting the two halves of the aluminum extrusion adjacent the polyurethane thermal barrier. This is called "skip-debridging." Such a removal process provides structural integrity while allowing only a negligible amount of heat loss through the remainig bridge portions. The channel pockets for holding the hardened polyurethane thermal barrier in the aluminum extrusion are commonly angular or of a square C-shaped configuration. Conventionally, only one thermal end pocket is provided for each half of the aluminum extrusion to hold the thermal barrier in place therebetween.
Problems of conventional aluminum window frame extrusions are many. Single, square-shaped thermal pockets often do not tightly hold a polyurethane thermal barrier in place. Conventional configurations often do not hold the thermal barrier in place with even pressure. Conventional extrusions with square-shaped thermal end pockets have separate screw locking ports that do not adequately retain screws or bolts which are positioned longitudinally therein to, for example, hold a window frame together, since screws only bite into an aluminum port in a conventional extrusion and not into insulation as well, which helps lock screws into place, and this limited "bite" may not allow the necessary torque to sufficiently hold a window frame together. Separate screw locking ports also take up space, which may be at a premium when a compact extrusion is required. Conventional de-bridging leaves a jagged, sharp edge on one side of the extrusion, which can be dangerous and gives an unfinished appearance.
Thus, with the problems and disadvantages of the prior art window frame extrusions, the present invention was conceived and one of its objectives is to provide a window frame extrusion utilizing the desired characteristics of both wood and aluminum.
It is another objective of the present invention to provide a window frame extrusion which has a thermal barrier.
It is yet another objective of the present invention to provide a window frame extrusion which has a thermal barrier with an internal structural reinforcement.
It is also an objective of the present invention to provide a window frame extrusion with a pocket for more effectively holding and retaining a thermal barrier.
It is still another objective of the present invention to provide a window frame extrusion having a thermal barrier end pocket which more evenly distributes loads on the thermal barrier.
It is yet another objective of the present invention to provide a window frame extrusion that has improved torsional resistance.
It is a further objective of the present invention to provide a window frame extrusion that allows heavier loading.
It is additionally an objective of the present invention to provide a window frame extrusion that has a smooth, finished appearance on both sides of the insulation component.
It is also an objective of the present invention to provide a window frame extrusion with a thermal barrier end pocket having an integral screw locking port which enables a threaded member to secure a firm grip on the extrusion in a window frame installation.
It is still another objective of the present invention to provide a window frame extrusion that is more compact than conventional window frame extrusions having separate screw locking ports.
It is a further objective of the present invention to provide a method of making a window frame extrusion with the aforementioned characteristics.
Various other objectives and advantages of the present invention will become apparent to those skilled in the art as a more detailed description is set forth below.